Almost a half-million displaced Syrians have returned to their homes since the beginning of the year, mostly to check on property and relatives, according to estimates from the United Nations.

The U.N. refugee agency said Friday it had seen a "notable trend of spontaneous returns" this year, and estimated that more than 440,000 internally displaced Syrians and another 31,000 refugees who left the country had returned home.

Andrej Mahecic, a spokesman for the agency, told reporters Friday in Geneva that it marked "a significant trend and a significant number." He said people returning home were "seeking out family members, checking on property, and, in some cases, a real or perceived improvement in security conditions in parts of the country."

He cautioned, though, that the returnees are "only a small fraction" of the roughly 5 million Syrian refugees estimated to have fled the country.

More than 320,000 people have been killed since the Syrian civil war began in 2011.